Place the mouse at the opposite end of the snake, and just keep an eye on things. There are no need for tongs since the mouse is alive and would bite and try to get away. The snake knows what it is doing and knows what kind of grip is needs to keep the mouse from biting him. If you just let nature take its course, all should go well. In the event of a small bite, if it does occur, just apply some neosporin and all will be well again.

Hope that helped a bit and settled some of your fears about feeding your snake